20664243 has 6 divisors (see below), whose sum is σ = 29848364. Its totient is φ = 13776156.

The previous prime is 20664239. The next prime is 20664257. The reversal of 20664243 is 34246602.

It is not a de Polignac number, because 20664243 - 2² = 20664239 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20660243) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1148005 + ... + 1148022.

Almost surely, 2^20664243 is an apocalyptic number.

20664243 is a deficient number, since it is larger than the sum of its proper divisors (9184121).

20664243 is a wasteful number, since it uses less digits than its factorization.

20664243 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2296033 (or 2296030 counting only the distinct ones).

The product of its (nonzero) digits is 6912, while the sum is 27.

The square root of 20664243 is about 4545.7939900528. The cubic root of 20664243 is about 274.4141489515.

The spelling of 20664243 in words is "twenty million, six hundred sixty-four thousand, two hundred forty-three".